A grand jury has charged former Penn State president Graham Spanier with participating in a "conspiracy of silence" to cover up child sex abuse by former football coach Jerry Sandusky, Pennsylvania's attorney general said.

The highest-ranking Pennsylvania State University official charged in the explosive case, 64-year-old Spanier was accused on Thursday of child endangerment, perjury and criminal conspiracy, all felonies. He also faces misdemeanour counts of failure to report suspected abuse, conspiracy and obstruction of the administration of law.

"This is not a mistake, an oversight or a misjudgment. This was a conspiracy of silence by top officials at Penn State, working to actively conceal the truth, with total disregard to the suffering of children," Attorney General Linda Kelly said.

Two other officials, athletic director Tim Curley and retired vice-president Gary Schultz, also face new charges of child endangerment, criminal conspiracy and obstruction. They were charged in November 2011 with failure to report suspected abuse and perjury, and both have pleaded not guilty.

Sandusky, 68, a former assistant coach in Penn State's powerhouse football programme, was convicted in June of molesting 10 boys over a 15-year period in a scandal that rocked US college sports and focused national attention on child sex abuse.

He was sentenced to 30 to 60 years in prison, effectively a life sentence.

This article appeared in the South China Morning Post print edition as Ex-Penn State president charged in Sandusky case